A Mini LED (Mini Organic Light-Emitting Diode) is based on tiny LED crystal particles as pixel light-emitting points. When used as a surface light source for display devices, it can achieve high contrast, high brightness, and high color gamut. Moreover, HDR (High-Dynamic Range) effect can be achieved by partitioning the surface light source.
In the case of using the Mini LED as a surface light source for a display device, it is common to adopt a direct-type configuration in which a quantum dot (QD) film is arranged above a chip substrate of the Mini LED surface light source. The light mixing principle of the Mini LED surface light source lies in that the Mini LED chip emits blue light which is mixed with red and green light emitted by the excitation of the QD film to form white light. The QD film mainly includes a quantum dot functional layer, which requires high water and oxygen isolation and is sealed by two layers, i.e., upper and lower package layers.
The upper layer of the traditional QD film needs to be separately provided with a prism sheet to achieve light gathering, and the lower layer needs to be separately provided with a diffusing film, so as to improve the brightness uniformity of the Mini LED surface light source. In this way, the entire optical device has a complicated overall modular structure with a relatively large thickness.